Swimming pool, respiratory health, and childhood asthma: should we change our beliefs?

Swimming is often recommended as a sport because of its several benefits to health. It is also recommended in asthmatic children as a sport with a lower potential for prompting exercise-induced asthma. However, there is growing interest in the potentially harmful effects of repeated respiratory tract exposure to chlorinated products and the problem of possible swimming-related health hazards is gaining importance at international level. It is already known that acute exposure to chlorine gas as in swimming pool accidents causes lung damage and also that elite swimmers may have increased airway inflammation and bronchial hyperreactivity, probably as a result of repeated exposure to chlorine derivatives. Recently some studies have been conducted to investigate whether repeated exposure to chlorine by-products in recreational swimmers might also lead to lung damage. In addition, some studies have been lately published on the even more debated issue of the possible harmful effects of baby swimming on respiratory health. This article reviews and discusses data from the literature on the effects of chlorine derivatives in different categories of people routinely attending swimming pools. The need for longitudinal studies is emphasized to definitely clarify any role of chlorinated swimming pool attendance in the development of asthma in recreational swimmers.